This invention relates to the art of electric lamps, and more particularly to a new and improved portable electric lamp of explosion-proof construction.
One area of use of the present invention is in illuminating mines and similar work environments containing explosive gases although the principles of the present invention can be variously applied. Portable work lamps or extension lamps must be of explosion-proof construction to satisfy safety requirements of mines and other hazardous working areas. In particular, such lamps should be adequately enclosed or sealed against entry of explosive gas, should be of a construction which limits or confines any internal explosion and its effects in the event that one does occur in the lamp, and should withstand impacts and shocks which occur in dropping and bumping of the lamp. Along with satisfying these and other safety requirements, it is desirable to provide such a lamp which is portable, light in weight, easy to use in confined areas, provides adequate illumination and is simple in construction and easy to maintain.